Diaphragm-mounting



C. N. WARNER.

DIAPHRAGM MOUNTING.

APPLICATION FILED APR.28. 1920.

1,372,054, Patented Mar. 22, 1921.

UNITED STATES PATENT OFFICE.

CHARLES N. WARNER, OF NEW YORK, N. Y.

DIAIPHRAGM-MOUN TING.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application f led April 28, 1920. Serial No. 377,162.

. invented certain new and useful Improvements in Diaphragm-Mountings, of which the following is a full, clear, and exact description.

This invention relates to diaphragm mountings for acoustical instruments and similar devices, and has especial value when used in talking machine sound boxes.

One object of my invention is to provide a mounting which will support the diaphragm in a proper operative position and yet permit of a response by the diaphragm to sound waves or the oscillations of a stylus, which will be as free as possible from the restraints of mechanical parts and thus obtain a more perfect reproduction or recordation.

A further object is to provide a diaphragm mounting which is readily adaptable for use in sound boxes for talking machinesjand the. like, and which is durable in use and inexpensive.

A further object is to provide a diaphragm mounting which will generally improve the quality of the sound emitted by the instrument containing the same.

Other objects and advantages will be apparent from the following description and the novel features of my invention will be particularl pointed out in claims.

In one 0 its aspects my invention comprehends a peripheral groove or recess containing a heavy viscous substance such as a heavyoil or petroleum jelly over which the diaphragm is placedwith a face in contact with the viscous substance.

It also comprehends the support of the diaphragm'on one side by means of small diametrically opposed abutments for slightly tion. In the drawings:

embodiment of my invention;

Fig.2 is a front elevation ofthe casing v and diaphragm, the latter being partly broken away to show certain details; Fig. 3 is a partial sectlonal elevation of a slightly modified construction;

limiting vibratory movement in one direc- 3 by suitable means such as screws 4 is an annular ring 5 having a flange 6 extending from its inner periphery into the chamber 2 to form with the flange 8 an annular or peripheral'groove 7. The groove is filled with a suitable viscous substance 8 such as heavy oils or petroleum jelly, and the diaphragm 9 is positioned in the chamber 2 with one face thereof covering the groove and in contact with the viscous substance 8. For slightly limiting the vibratory movement of the diaphragm I may provide on the casing in the depression 2 a pair of small abutments 10, disposed between the diaphragm 9 and casing l and on the side of the diaphragm opposite from'the flange 6. The abutments 10 are also arranged along substantially diametrically opposed edges of the diaphragm. The diaphragm may be of any suitable material such as those commonly in use, but if it is of wood, the abutments 10 are preferably arranged at the ends of a diameter of the diaphragm which extends transversely of the grain of the wood, since the flexure of the diaphragm is, in such a case, along the grain of the wood which I have found provides a more sensitive instrument. The abutments may be omitted if desired, although I have found their use to be desirable.

In order to prevent egress of the viscous substance during long continued use I may line the groove with one or more of the flexible strips 11 and 12 which project from the groove toward and into ngagement with the diaphragm to thus more effectively confine the viscous substance.

' I may also form the annular ring 5 and its flange 6 of a slightly flexible yielding material such as rubber, or construct it of the shape indicated in Fig. 4. I may also provide'the groove and viscous substance on both sides of the diaphragm, if desired, as

' or heavy v oils as suitable fillers for the grooves I do not desire to be limited thereto as various other jellies or viscous substances may be used equally Well. The other parts may be of any suitable material and for the lining strips I have found waxed or glazed paper to be very satisfactory. With a talking machine sound box provided with a diapraghm mounted in accordance with my invention, I find the tones and sound waves produced thereby to be clearer, more distinct and round, and generally more natural and pleasing. I find that with such a box, very low or faint sounds such as those of the piano or harp which heretofore have been diflicult of satisfactory reproduction, are reproduced in a clear, loud, and natural manner, while the box is equally satisfactory, when used with records having notes of a ver high pitch. I have also found that the eavler the oil or viscous substance the more prominently will the bass be brought'out. Heretofore difficulty has been experienced by so-called blasting of the diaphragm when notes of high frequency are being reproduced, but with a box having my invention embodied therein -blasting is prevented or avoided.

It is obvious that various changes in the embodiments herein described and illustrated may bemade within the principle and scoIpe of my invention.

claim:

1. A. diaphragm mounting comprising a support provided with a peripherally arranged groove, a viscous substance filling said groove, and a diaphragm having one face covering said groove and in contact with the viscous substance.

2. A diaphragm mounting comprising a support provided with a peripherall extending groove, a viscous substance lling said groove, a diaphragm having one face covering said groove and incontaot with the viscous'substance, and a pair of short abutments along the peripheral portion on opposite sides of the center of the diaphragm and on the side opposite from the groove for slightly limiting the movement of the diaphragm away from the groove.

3. A diaphragm mounting comprising a support provided with a peripherally extending groove, a viscous substance filling said oove, a diaphragm having one face covering said groove and in contact with the viscous substance, and a flexible lining memher in said groove extending outwardlyinto contact withv the diaphragm.

4. A diaphragm mounting comprising a support provided with a peripherally extending groove, a viscous substance filling said roove, a diaphra having one face covering said groove an in contact with the viscous substance, 2. pair ofshort abutments along the. peripheral portion on opposite sides of the center of the diaphragm and on the side 0 posite from the groove for slightly limiting the movement of the diaphragm away from the groove, and a flexible lining member in said groove extending outwardly into contact with the diaphragm.

5. diaphragm mounting comprising a support provided with a 'resilient portion extending from and forming with the re-v mainder of the support a peripherally extending groove, a viscous substance filling said groove, and a diaphragm having one. face coveringthe groove and in contact with the viscous substance.

' 6. A diaphragm mounting comprising a support provided with a resilient portion extending from and forming with theremainder of the support a peripherally extending groove, a viscous substance filling said groove, a diaphragm having one face coverlng the groove and in contact wlth the viscous substance, and a flexible lining in' said groove extending outwardly into engagement with the diaphragm.

7 A. diaphragm mounting comprising a frame, a rubber extension on said frameforming therewith a peripherally extending groove, a viscous substance filling said groove, and a diaphragm withinthe frame and having one face covering the groove and in contact with the viscous substance.

8. A diaphragm mounting comprising a frame, a rubber extension on said frame forming therewith a peripherally extending groove, a viscous substance filling said groove, a diaphragm within the frame and having one face covering the groove and in contact with the viscous substance, and a flexible lining in said groove extending outwardly into engagement with the diaphragm.

9. A diaphragm mounting comprising a frame, a rubber extension on said frame forming therewith a peripherally extending groove, a viscous substance filling said groove, a diaphragm'within the frame and having one face covering the groove and in' contact with the viscous substance, and means abutting the side of the diaphragm opposite from the groove for slightly limiting movement of the diaphragm away from my signature.

CHARLES N. WA RNER. 

